Just to be absolutely clear: Briggs did not suggest using conservative
coalescing in the normal case, only in the very limited context of
un-splitting live-range splits. His allocator used agressive
coalescing normally. Krall may well have known this, and Moon and
Park (whom he cites) certainly did, and say as much. But I have run
into a number of people who do not know this, and the comments quoted
above might well reinforce their mis-understanding.

So far as I know, it is Appel and George who first applied
conservative coalescing as the normal coalescing scheme. Appel's book
has been spreading this idea rather widely. But it is not Briggs's.